Improvement in processes for preserving wooden pavements from rot



'UNITED STATES PATENT OFFIcE.

IMPROVEMENT IN PROCESSES FOR PRESERVING WOODEN PAVEMENTS FROM ROTISpecification forming part of Letters Patent No. 126,592, dated May 7,1872.

To all to whom it may concern:

Be it known that I, AROHIB'ALD B. TRIP- LER, of Philadelphia, in thecounty of Philadelphia and State of Pennsylvania, have invented acertain new and useful Process for Preserving Wooden Pavements from Rot,&c., of which the following is a full, clear, and exact description.

Letters Patent No. 104,917 were granted to me June 28, 1870, forpreserving wood for railroad ties and other purposes, in which the useof chloride of arsenic, or arsenic and chloride of sodium combined, areclaimed as the preservative agents, as therein described. In my presentapplication for Letters Patent I use the same antiseptics, after firstpreparing the blocks and foundation timbers or planking of the pavement,in a manner as follows: The foundation timbers or planking and theblocks forming the pavement are first placed in a suitably-constructedcylinder or other receptacle, through which a volume of superheatedsteam is passed to free the pores of the wood from sap. Whensufficiently steamed, a current of superheated dry air is then passedthrough the cylinder until the blocks and planking are sufficientlydried, which leaves them in a cellular condition, and in a state toreceive the antiseptic, which thoroughly permeates the tissues of thewood and prevents dry rot or fermentation. The foundation planking ofthe pavement is then laid securely in position, and the antisepticspread upon it so that the wood will cover it, and it is then ready toreceive the blocks. These latter are also immersed a sufficient lengthof time in the antiseptic solution or compound until they are like- Iwise thoroughly saturated, and their upper ends are then immersed in asuitable waterproof composition-it may be of asphaltum or mineral pitch,coal-tar, and charcoal, or other available substance, to render theirsurface impervious to moisture and prevent the antiseptic, which ishighly soluble, from being diluted by rain, &c. Or the blocks may beplaced in position, and the waterproof composition spread over andbetween them, as may be found most desirable.

The process herein described I have found to remedy the great objectionheretofore urged against the adoption and use of wooden pavements, forthe moisture arising from the earth cannot injure the foundationplanking, the sap and all perishable matter-having been removedtherefrom, and in its place the antiseptic acts as a barrier between themoisture of the earth and the blocks, while the latter, being similarlytreated, and coated upon their upper surface with a water-proofcomposition, are incased, as it were, between stratums of preservativeagents, through which moisture cannot penetrate.

Instead of a foundation plankin gbein g used, the blocks may be placeddirectly upon the sand. In this case the antiseptic compound may be usedin a dry state, and either be mixed with the sand or be placed upon it,in either of which cases its preservative action on the wood above itwill be the same.

Having described my invention, I claim-'- 1. The process hereindescribed for protecting wooden pavements from rot.

2. The blocks constituting a wooden pavement, saturated with a solutionof chloride of arsenic, or arsenic and chloride of sodium, and coated ontheir upper surface with a waterproof compound, as herein described.

3. The interposition of an antiseptic compound between the blocksforming the pavement and the earth by the saturation therewith of thefoundation planking, or its admixture with sand, as herein described.

In testimony whereof I have hereunto signed my name.

A. B. TRIPLER. Witnesses:

JNo. J. NORTON, H. H. YOUNG-

